After some hesitation and nudging from Kris make the following changes:
. make compile with and default to Tcl-8.4 (8.3 is still possible)
(this necessitated PORTREVISION bump :\)
. don't link in -lgcc -- should've used gcc_pic anyway, but this
is not really needed at all, it seems;
. don't require a particular version of mysqlclient library.